The present invention deals generally with the field of archery bow string release aids, (although one skilled in the art could adapt the basic design for other uses, such as the fire control system of a firearm). Such release aids are well established in the art and are generally intended to serve two essential functions: to alleviate strain on the archery's fingers while drawing and holding the bow and to provide an accurate, repeatable, mechanism for releasing the bowstring. In other words, these devices are generally intended to permit the archer to concentrate on his intended target, while being able to ignore the mechanical aspects of releasing the bow string.
Archery release aids are well established in the art, and take on various forms. There are releases that rely upon holding and releasing the nock of the arrow. See, e.g., Maxwell, U.S. Pat. No. 1,542,159 and Cook, U.S. Pat. No. 4,151,825. Others rely upon pivoting or clamping jaws to hold and release the bow string. See, e.g., Vogel, et. al., U.S. Pat. No. 5,067,472; Greene, Jr. U.S. Pat. No. 5,020,508; Lyons, U.S. Pat. No. 4,282,851 and U.S. Pat. No. 4,407,260. Other devices use a variety of triggers, sears, cams, and a variety of mechanical motions to achieve the desired results. See, e.g., Gazzara, Sr. U.S. Pat. No. 3,948,243; Scott, U.S. Pat. No. 4,036,204; Peck, U.S. Pat. No. 4,881,516 and U.S. Pat. No. 5,103,796; and Summers, US Appl. No. 20040079351. However, the bow string releases presently available do not achieve the ease of use and consistency required for the archer to achieve the utmost accuracy. It is the purpose of this invention to overcome the deficiencies found in the prior art devices and to provide an archery release of superior accuracy and repeatability.
The present invention accomplishes its purpose using three improvements over the prior art. First, the device's design eliminates the sear commonly found in existing designs. As described further herein, eliminating the sear and mechanically disconnecting the movement of the trigger from the second stage cam, the sensation of “creep,” i.e., the physical sensation of the sear dragging across its engagement surface prior to firing, is eliminated. Eliminating the sensation of creep allows the archer to concentrate on his or her target and not on the movement of the release's trigger.
Second, the preferred embodiment of the design of the first and second stage of the trigger results in trigger travel amplification. That is, a movement of X of the first stage trigger (FIG. 1 (3B)) results in a movement of approximately 1.5× at the terminus of the second stage trigger cam (FIG. 1 (6B)). Again, by minimizing the physical movement required to release the bowstring, the more the archer can concentrate on his or her target, and not on the movement of the trigger.
Finally, this invention allows for an infinitely adjustable trigger pull. The archer, by changing springs (FIG. 1 (9)) and the amount of tension placed upon those springs by spring retention screw (FIG. 1 (10)) can vary the trigger pull from a few ounces to several pounds. Thus, this design will accommodate a wide range of shooting styles, including those shooters who prefer shooting with back tension.